The present invention relates to a semiconductor package and a semiconductor device using the semiconductor package, and more particularly to a semiconductor package including a flip-chip connecting pad and a land pad to be used for a BGA (Ball Grid Array) or LGA (Land Grid Array) connection, and a semiconductor device using the semiconductor package.
In a semiconductor package to be used for a portable telephone or a digital camera and a semiconductor device using the semiconductor package, an increase in a density and a reduction in a size have been desired. In an assembling technique of the semiconductor package and the semiconductor device which have densities increased and sizes reduced, a flip-chip connecting structure of a semiconductor chip is employed as effective means.
In the flip-chip connecting structure, an interval between the semiconductor chip and a substrate of the semiconductor package in a chip mounting area is very small, that is, approximately 30 μm in a high density connecting structure. For this reason, a resin having a low viscosity is used for an underfill resin.
In the case in which the underfill resin having a low viscosity is used, the underfill resin flows out of a flip-chip connecting region more or less. Conventionally, an appearance is slightly deteriorated and can be disregarded. When the size of the semiconductor chip itself is reduced and mounting densities of the semiconductor chip and other electronic components are increased, however, there is a possibility that the flow-out of the underfill resin might adversely influence the peripheral chip and electronic components.
In recent years, there is a laminating type semiconductor device formed by mounting another semiconductor device on a semiconductor device having a semiconductor element flip-chip connected and connecting the semiconductor devices to each other through an LGA connection. In the semiconductor device, there is required a method of forming a dam for preventing the flow-out of an underfill resin through a protecting resist layer provided to surround a chip mounting region in such a manner that the underfill resin does not flow to a BGA connecting or LGA connecting land pad disposed on an outer side of a chip mounting region of a semiconductor package.
[Patent Document 1] JP-A-2006-351559
FIG. 14 is an explanatory view showing a step in the middle of a manufacture of a semiconductor package including a flip-chip connecting pad and a BGA or LGA connecting land pad.
A bump 12 (gold bump) formed on a semiconductor element 10 (see FIG. 12) is bonded to a flip-chip connecting pad 16, while a solder ball or a connecting pin is connected to a BGA connecting or LGA connecting land pad 18. For this reason, a solder is clad to a surface of a copper pad in the flip-chip connecting pad 16. Also in the BGA connecting or LGA connecting land pad 18, moreover, a copper pad can also be used. In order to cause the land pad 18 to be more suitable, however, it is desirable that a plating 36 (for example, a nickel plating and a gold plating) should be applied to the surface of the copper pad.
In the case in which the nickel plating and the gold plating are applied to the land pad 18, a wiring pattern, the flip-chip connecting pad 16 and the land pad 18 are formed on a surface of a substrate 14, and subsequently, the plating 36 is first applied to a pad portion serving as the land pad 18 and a solder 52a is thus clad to a pad portion serving as the flip-chip connecting pad 16 at a step of forming the substrate 14.
More specifically, a pad portion 16a serving as the flip-chip connecting pad 16 is coated with a plating resist to apply the plating 36 when the plating 36 is to be applied to a pad portion 18a serving as the land pad 18, and a masking tape 42 is stuck to the land pad 18 and the land pad 18 is thus coated when the pad portion 16a serving as the flip-chip connecting pad 16 is to be solder coated with a solder powder 52.
The land pad 18 is provided in an outer region surrounding a region in which the flip-chip connecting pad 16 is formed, and a dam D is formed by a protecting resist layer to surround the region in which the flip-chip connecting pad 16 is formed. The dam D serves to prevent an underfill resin 37 (see FIG. 12) from flowing to a region in which the land pad 18 is formed and is provided to be protruded upward from a resin substrate 30 or a solder resist 38. As described above, the masking tape 42 is stuck to shield the land pad 18. However, the masking tape 42 cannot be flatly stuck into the region in which the land pad 18 is formed because the dam D is formed. For this reason, there is a problem in that a clearance S is generated between the masking tape 42 and the region in which the land pad 18 is formed as shown in FIG. 14. In the case in which the pad portion 16a serving as the flip-chip connecting pad 16 is solder coated with the solder powder 52, a sticky solution is adhered to the pad portion 16a. When the sticky solution is supplied in this state, accordingly, the sticky solution flows from the clearance S between the region in which the land pad 18 is formed and the masking tape 42 into the region in which the land pad 18 is formed or the solder powder 52 is adhered to the land pad 18 so that the plating 36 on the surface of the land pad 18 cannot be protected, resulting in a defective product.